“The chart above, which should look familiar, shows the two peaks in this long-term housing conundrum. The first mountain is comprised of subprime ARM resets. And the second is mostly constructed of option ARM resets. We appear to be in the eye of the storm.

These types of loans are also called "pick-a-payment" or "pay-option" ARMs.

When a borrower makes a Pay-Option ARM payment that is less than the accruing interest, there is "negative amortization", which means that the unpaid portion of the accruing interest is added to the outstanding principal balance. For example, if the borrower makes a minimum payment of $1,000 and the ARM has accrued monthly interest in arrears of $1,500, $500 will be added to the borrower's loan balance. Moreover, the next month's interest-only payment will be calculated using the new, higher principal balance.